M3.9 Earthquake 180 km SE of Sand Point, Alaska — October 19, 2020
2020-10-19 23:38:08 UTC (2020-10-19) · approx. 12:38 PM UTC-11 local
On October 19, 2020 at 23:38 UTC, a magnitude 3.9 shallow crustal earthquake struck 180 km SE of Sand Point, Alaska, at a depth of 16.4 km and coordinates 54.3333°, -158.2930°.
Physical scale: An earthquake of magnitude 3.9 releases seismic energy equivalent to roughly 11 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 296 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
-158.2930°E
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Common Questions
How strong was the magnitude 3.9 earthquake near Sand Point, Alaska?
The magnitude 3.9 earthquake that struck 180 km SE of Sand Point, Alaska on October 19, 2020 at 23:38 UTC had a depth of 16.4 km. For context, this was a minor earthquake typically detected only by instruments.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 3.9 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 3.9 earthquakes are typically only recorded by instruments.
Authoritative source: USGS event page (event ID: us6000cc2p). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2020, October 19, 2020). M3.9 Earthquake 180 km SE of Sand Point, Alaska — October 19, 2020. Retrieved December 29, 2020 from https://www.earthquaketracker.org/earthquakes/event/us6000cc2p/